Briggs and Stratton Auto Choke Problem/Mystery.

Sabres321

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Hey! I’m new here and have run into an issue with a couple of mowers with the same Briggs and Stratton 190 cc auto choke system that I just can’t seem to solve. One is a Husqvarna, the other a John Deere (just got it today, wasn’t working.)

I’ll start with the Husqvarna. I received it in a trade, it’s an awd mower in really nice shape. I ended up getting it to start and it ran great. Then after letting it sit for a while, for some reason it wouldn’t restart. To make a long story short, I pretty much changed everything out (carb, auto choke parts, spark plug) and still, same problem. I noticed that when it would do this, the choke was shut. My dad suggested to hold the choke open while he tried to start it, and it did the trick. So I ordered a brand new thermostat to see if this might cure the problem, and still! After letting the engine cool down for about 20 minutes after use, would not start unless we helped it by opening the choke...

So with the John Deere mower, (again I’ll shorten the story here) it would struggle to stay running unless I kept it on full choke. After cleaning the carburetor (it is brand new) a couple of times, checking the auto choke parts, I ended up finding out the intake manifold had a big crack underneath it. After swapping it out, it started up and ran perfect! However, after about 20 minutes I went to start it and it wouldn’t go (ughhh). It reminded me of the Husq, so I checked the Choke (it was shut), opened it, my dad gave it a pull and it started right up no problem!

So I’m stumped on this. I’ve had many of these mowers, repaired many of these kinds of mowers, and these are the only two that have given me this problem. Has anybody else ran into this problem? Am I missing something? Also wanted to add that after getting it started and letting it warm up a bit, it’ll have no problem restarting unless I let it sit for another 20 minutes or so.
 

bertsmobile1

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Run the mower for 20 minutes then very quickly remove the filter housing and top cover
Bend the link from the thermostat to the choke out ( longer ) till it opens the choke fully.
let it get stone cold and double check that the choke is actually closed, if not back it off a little
This has been an on going problem for me on every one of these POS engines I have had the misfortune of being forced to work on.
You can also shorten the spring if it has on ( too many variations on this engine as well ) .
 

Sabres321

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I could try that, but just want to be clear that the thermostat is working as it should. It has no problem opening the choke and when the engine is warm the choke is wide open.
The problem occurs when the choke starts to close when the engine is off and cooling. Appreciate your feedback.
 

bertsmobile1

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I started off by bending the link rod as far as I could with the engine stone cold while allowing the choke to remain fully closed .
That seemed to work, sort of .
Working backwards seemed to work better.
Then there were the ones with a spring on the air vane that was too light and allowed the choke to flicker and of course the ones where the choke lever fouled on the side of the cover.
I Hate these engine with avengance .
I only see 3 or 4 a year and every one causes me mega grief.
 

gotomow

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When I was looking at the Toro super recycler I read the reviews of the model with the briggs 190cc. All the bad reviews revolved around the choke system.
 

Sabres321

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I started off by bending the link rod as far as I could with the engine stone cold while allowing the choke to remain fully closed .
That seemed to work, sort of .
Working backwards seemed to work better.

Are you referring to the newer briggs engine with the plastic carb?

I’m dealing with one like in this video here. However, if you are referring to this one, which link are you bending? Sorry, just I can’t picture the one you’re talking about.

I deal with these motors all the time, it seems like everybody has them over here. I deal with the newer ones every once in a while and they can be annoying lol.
 

StarTech

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Since there is two different auto choke used we need to which one you are working on.
 

tom3

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And I've often wondered why Briggs is so persistent on blocking that cooling air for the engine. Either a governor or now the choke deal. I took that choke deal off my mower with this deal on it. Another solution looking for a problem.
 

Sabres321

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Since there is two different auto choke used we need to which one you are working on.

Just stated, the one in the video (YouTube link I attached to my comment) is the one I’m working on.

It sounds like bertsmobile may be talking about the newer Briggs and Stratton auto choke with the plastic carb.
 

StarTech

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Make sure to check all the adjustments in the following service bulletin first.

SB760
 
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